RU2115821C1 - Intake system of internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering; automobile internal combustion engines. SUBSTANCE: system has air cleaner 1, mixed air pipe 2, heated and cold air branch pipes 3 and 4, respectively which have open ends 5 and 6, air flow temperature control member and device to suppress acoustic resonances and low frequency pulsation of gases in members of engine intake manifold. Pipe 2 and branch pipes 3 and 4 are of equal length L. Temperature control member is made of sound reflecting material and mounted on open ends of 5 and 6 of branch pipes 3 and 4. Gates 7 and 8 operate in OPEN or CLOSED positions. Device to suppress acoustic resonances and low frequency pulsations of gas is made in form of quarter wave resonator formed by one of branch pipes, 3 or 4 in which gate 7 or 8 is in CLOSED position. EFFECT: improved acoustic and other operating characteristics of automobiles. 2 cl, 5 dwg

Description

 The invention relates to engine building, in particular to the intake systems of an internal combustion engine (ICE) with improved acoustic and operational performance.

 One of the most difficult problems in modern automotive industry is the problem of reducing the noise level of the intake of an internal combustion engine, which is excited as a result of intense pulsations of the gas stream in the inlet tract of a working engine and is emitted by the inlet section of the intake pipe into the environment.

 Various technical methods are known that make it possible, to one degree or another, to solve a designated problem.

 So, in the intake system of the carburetor engine described in the USSR copyright certificate N 871570, class. F 02 M 31/00, 1984, the supply pipes to the cold and heated air purifier are equipped with calibrated holes located at a certain distance from the open ends of the pipes, corresponding to the placement of these holes in the zones of maximum sound pressure for the first and second modes of vibration (mod), which allows you to effectively suppress resonance phenomena in these modes.

 Recently, two-pipe (thermostatically controlled) intake systems have been most widely used, with 1/4 wave resonators connected in a certain way to their pipes. Such designs of intake systems are described, for example, in EPO 0192457, cl. F 02 M 35/12, publ. 1986, EPO 0091038, class F 02 M 35/12, publ. 1983, US Pat. No. 5,040,495, cl. F 02 M 35/10, publ. 1991, Japanese application 61 - 190158, cl. F 02 M 35/12, publ. 1987, EPO 0379926, class F 02 M 35/12, publ. 1990 and others

 All the technical solutions mentioned provide for the use of an additional dead-end waveguide (pipe with a blind end) connected to the air intake pipe or to the air purifier chamber, which (the resonator) performs only an acoustic function and in some cases causes deterioration of other functions and performance of the vehicle. In particular, these are the problems of layout in cramped space of the engine compartment (the length of the resonator pipe reaches a meter), the growth of material consumption and cost, the possible ingress of water into the pipe and the need to remove it, for example, due to a special hole in the bottom of the resonator, as noted Japanese Application (B) 2-9175, CL F 02 M 35/12, publ. 1990. It should be noted that the known solutions do not fulfill other absolutely necessary functions (not multifunctional), such as, for example, eliminating overheating, warping and melting of the hot air intake pipe and thermostat damper, eliminating engine breakdown due to possible hydraulic shock of the piston in the zone of top dead center when water is sucked through the cold air intake pipe when the car moves through the ford or when driving in conditions of heavy snowfall.

 As a prototype, a temperature-controlled intake system for a multi-cylinder engine is described in the USSR author's certificate N 871570, class. F 02 M 31/00, publ. 03/07/84, Bull. No. 9, comprising an air purifier, a mixed air pipe, heated and unheated air pipes equipped with open ends, an air flow temperature control element (a temperature regulator to which the pipes are connected) and a device for suppressing acoustic resonances and low-frequency gas (air) pulsations in the internal combustion engine intake duct elements , which is represented by calibrated holes made in the pipes, or at least one of them, at a distance of 0.25. . . 0.5 of their total length from their free ends. In addition, the ratio of the total area of the bore of the holes to the cross-sectional area of the corresponding pipe is 0.01 ... 0.08.

 The described system has the advantage that it does not present any technical difficulties in implementation. This means that the perforation of the nozzles is structurally simple and high-tech technique. Until recently, such a system completely satisfied the requirements that were imposed on the permissible noise level of passenger cars. However, modern requirements dictate more stringent conditions, in connection with which more radical measures were required to suppress intake noise, for example, the introduction of Helmholtz resonators and / or 1/4 wave resonators into the intake path, as mentioned above. In addition, through open sections of nozzles into the intake tract, when the vehicle is wade or in conditions of heavy snow, water may enter, which in some cases leads to water hammer in the engine cylinder and its inevitable breakdown.

 The purpose of the invention is to improve the acoustic and operational qualities of the engine.

 The essence of the invention lies in the fact that in the known intake system of an internal combustion engine containing an air cleaner, a mixed air pipe, nozzles of heated and unheated air, equipped with open ends, an element for thermo-regulation of air flows and a device for suppressing acoustic resonances and low-frequency pulsations of gas in the intake duct elements ICE, mixed air pipe and nozzles of heated and unheated air have the same length, the element of thermoregulation of air flows made in the form of two rotary shutters equipped with a controlled drive, made of dense, gas-tight, sound-reflecting material and mounted on the open ends of the pipes of heated or unheated air and working in two positions “open” - “closed”, and when one of the shutters is fully open, another damper is completely closed, and a device for suppressing acoustic resonances and low-frequency gas pulsations is made in the form of one of the nozzles with a damper in the "closed" position.

 The damper actuator can be manual or automatic. The automatic drive, in turn, includes a temperature sensor located in the mixed air pipe, near the air cleaner chamber (or in the chamber itself), which sends a signal to the processor, the control pulses from which are supplied to the actuating power mechanisms that move the shutters.

 To increase the compactness and efficiency of the heated air pipe, part of the pipe can be made in the form of a screw channel (screw) formed by the pipe walls and part of the outer wall of the exhaust manifold on which this pipe is rigidly fixed.

 With this design, in contrast to the prototype, where the resonance radiation of the twin pipes on the lower eigenmodes is suppressed by performing calibrated holes that play the role of dampers (forcing gas pressure fluctuations through small perforation holes), the proposed system provides significantly more effective antiphase compensation sound fields 1/4 wave resonator, which in the ideal case implies the complete destruction of the direct wave field reflected in otivophase.

 In addition, in the prototype, through open calibrated openings, high-frequency sound energy is "highlighted", which is not in the 1/4 wave resonator and in a dead end (isolated from the environment) branch. Moreover, making holes of a considerable diameter or vice versa of a significant number of small holes for individual frequencies, as it were, shortens the effective length of the pipe (the sound is emitted by the holes themselves, and not the open end of the pipe) and the oscillating mass of air between the belt of holes and the open end is excluded process. And the buildup of a lighter mass (shortened pipe) leads to an increase in the amplitudes of the oscillation velocities of this mass and, accordingly, to an increase in the radiated sound pressure at the inlet.

 In FIG. 1 shows a proposed intake system; in FIG. 2 is a diagram for connecting a 1/4 wave resonator to an air channel formed by a mixed air pipe and one of the nozzles; in FIG. 3 is a diagram of the distribution of sound pressure P on the first (Fig. 4 - on the third) lower intrinsic resonance form of air volume oscillations enclosed in an open channel on both sides formed by the internal cavities of the mixed air pipe and one of the nozzles; in FIG. 5 - a possible embodiment of the compact design of the heated air pipe mounted on the exhaust manifold of the engine.

 The intake system of the internal combustion engine contains an air cleaner 1, a mixed air pipe 2, nozzles 3 and 4, respectively heated and unheated air, equipped with open ends 5 and 6, an element for thermally regulating air flows and a device for suppressing acoustic resonances and low-frequency pulsations of gas in the intake duct elements ICE. The pipe 2 and pipes 3 and 4 have the same pipe L. The temperature control element is made in the form of two rotary shutters 7 and 8 equipped with a controlled drive, made of dense, gas-tight, sound-reflecting material and mounted on the open ends 5 and 6 of pipes 3 and 4. Damper 7 and 8 operate in the position of either “open” or “closed”, and when one of the shutters, for example 7, is open, the other (shutter 8) is closed and vice versa. A device for suppressing acoustic resonances and low-frequency gas pulsations is made in the form of one of the nozzles 3 or 4, in which the shutter 7 or 8 is in the "closed" position. In other words, this device represents a 1/4 wave resonator, in antiphase tuned to the first (and all odd) intrinsic resonance modes of vibration, see FIG. 3 to 4.

 The drive of the shutters 7 and 8 can be manual (cable or pull), it is widely known and is not shown in the drawings. Automatic drive, FIG. 1, includes a temperature sensor 9, which supplies a signal to the processor 10, the control pulses from which are transmitted to the actuating power mechanisms 11 and 12, moving the shutters 7 and 8.

 Part of the pipe 3 can be made in the form of a helical channel, FIG. 5 formed by the walls of the pipe 3 and part of the outer wall of the exhaust manifold 13, on which the pipe 3 is rigidly fixed. Structurally, a variety of options can be presented here, for example, the channel can be formed by a fixed screw guide element 14 (such as a screw) fixed to the wall of the collector 13, enclosed in a housing 15 on which there are windows for connecting the pipe 3 and its open end 5 with a shutter 7 In this embodiment, at the same time as compactness, the increased efficiency of heat removal from the surface of the exhaust manifold 13 is obvious, since the air entering through the open end 5 into the housing 15 repeatedly washes the wall hot collector 13.

 The proposed system provides that the force holding the shutter 7 of the nozzle 3 in the closed position only slightly exceeds the amount of rarefaction force that is formed above the shutter when the air is sucked in by the unheated air nozzle 4 with the carburetor throttle fully open and the engine is at maximum speed. This will be discussed in detail below.

 The proposed system works in the usual way.

 The pulsating air flow arising during the operation of the inlet valve causes a sound field to appear in the engine intake path, the energy of which is radiated into the environment by the open ends 5 and 6 of the nozzles 3 and 4. Sound emission is especially intense at the lower natural resonant frequencies of the air column enclosed in the nozzles connected to the air cleaner 1, see FIG. 3 to 4.

 To effectively suppress acoustic resonances and gas pulsations at these frequencies in the claimed system, it is proposed to use one of the standard branch pipes of the already known system as a 1/4 wave resonator tuned to the first lowest intrinsic resonant (and all odd) vibration frequency of the air enclosed in the pipe 2 - pipe 3 (with the shutter 8 closed), or pipe 2 - pipe 4 - with the pipe 4 (with shutter 7 closed). Those. when operating a car in summer, when an unheated air pipe 4 is used for air intake in the internal combustion engine, the pipe 3 with a closed shutter 7 performs the function of 1/4 of the wave resonator (the supply of warm air is excluded at this time). When operating a car in winter (at low ambient temperatures), the heated air pipe 3 is used, and the unheated air pipe 4 with a closed shutter 8 performs the function of 1/4 of the wave resonator.

 When the car moves through the ford (in conditions of positive ambient temperatures) and when water enters through the open end 6 into the nozzle 4, the conductivity of the nozzle 4 decreases sharply, while a vacuum increases sharply above the shutter 7 in the nozzle 3, which will make it open and provide the necessary supply of intake air to the internal combustion engine through the pipe 3 of the heated air. Thus, water through the pipe 4 in the engine cylinders will not get. After overcoming the ford, the power mechanism 11 will return the shutter 7 to the closed position, since the temperature state of the intake intake air corresponds to the operation of the engine in the summer (positive temperature range).

 Similarly, in conditions of negative ambient temperatures, when the pipe 4 is closed, performing at that time the function of 1/4 of the wave resonator, the snow falling into the zone of the open end 5, coming into contact with the red-hot wall of the manifold 13, melts instantly and can only enter the cylinders water vapor, which is completely safe (and in some cases even useful) for the engine.

 Thus, the use of standard pipes 3 and 4 of heated and unheated air not only for its intended purpose, but also for effectively suppressing intake noise, as well as giving the system a new quality - preventing water from entering the engine cylinders and thereby increasing its reliability and performance allows us to talk about its significant advantages in comparison with the adopted prototype.

Claims (2)

 1. The intake system of an internal combustion engine, comprising an air purifier, a mixed air pipe, heated and unheated air pipes provided with open ends, an element for thermally controlling air flows and a device for suppressing acoustic resonances and low-frequency gas pulsations in the engine intake tract elements, characterized in that the pipe mixed air and nozzles of heated and unheated air have the same length, the element of thermoregulation of air flows is made in the form of two controlled by a rotary damper actuator made of a dense gas-tight sound-reflecting material mounted on the open ends of the pipes of heated and unheated air and operating in two positions "Open" and "Closed", and a device for suppressing acoustic resonances and low-frequency gas pulsations is made in the form of one of nozzles with a shutter in the "Closed" position while the shutter of the second nozzle is in the "Open" position.  2. The system according to claim 1, characterized in that part of the heated air pipe is made in the form of a screw channel formed by the pipe walls and part of the outer wall of the exhaust manifold.

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